Mechanical resuscitator for combating asphyxia



Feb. 17, 1942. H, H, RAYMQND` 2,273,790

MECHANICAL RESUSCITATOR-FOR COMBATING AS'HYXIA` Filed April 2e, 19:59 l

Patented Feb. 17, 1942 MECHANICAL RESUSCITATOR FOR COMBATING ASKPHYXIAHorace H. Raymond, Berlin, Conn., assigner to William H. Stephenson, NewYork, N. Y.

Application April 26, 1939, Serial No. 270,216

' (o1. 12s-ao) 13 Claims.

This invention relates to improved apparatus for providing mechanicalresuscitation iny cases of asphyxie.

Asphyxiation occurs upon the failure of either cardiac or respiratoryaction. It has been found, that life continues in human `beings and thehigher animals so long as the exchange of oxygen and carbon dioxide iscontinued in a normal way in the blood and tissues of the body.Ventilation of the body through the lungs serves to maintain oxygen andcarbon dioxide in the tissues in proportion to their metabolic needs.Cardiac actionk through the-circulating blood accomplishes the supply ofoxygen to, and the removal of carbon dioxide from, the tissues of thebody. Circulation and respiration are thus interdependent and both areregulated by the gas pressure of oxygen and carbon dioxide in thetissues of the body, and respiration and circulation in turn serveduring life to maintain the gas pressures in the tissues substantiallyconstant in each part of the body. l

The reserve supply of oxygen in the human body is very limited, beingsufficient to maintain life for only a few minutes when all supply fromthe outside is cut off. Many kinds of illnesses greatly increase thespeed with which fatal as` phyxia may develop and it is thus mostimportant in severe cases of asphyxia that prompt treatment be begun asspeedily as possible to restore erator and/or patient, may be exposed toa grave risk of infection and of contracting disease.

Heretofore, complicated and expensive apparatus has been proposed formechanical resuscita- Cil tion. It is an object of my invention toprovide an improved, simple and dependable apparatus to produceartificial respiration by means of mechanically induced inhalations andexhalations; another object of my invention is to provide such a devicein such compact form that it maybe kept available for emergency usewithout taking up more than a minimum amount of space; another object isto provide a device in which the positive and the somewhat lessernegative pressures created in the patients lungs are accuratelycontrolled and limited; a further object of my invention is to provide adevice having means for mixing air with 'the oxygen supplied to `thepatient, and one which can be quickly conand maintain the properpressure of oxygen in the patients body. While the patient is stillbreathing, manual resuscitation b-y exerting pressure rhythmically onthe patients chest is possible. In more advanced stages when the patienthas. become flaccid, the lungs are collapsed in the position of extremeexpiration and the patients body lacks sucient elasticity forinhalations to be produced by the manual method. It is thereforenecessary to expand and deflate the lungs in a positive manner. This maybe done by the operator placing his mouth over the patients mouth and bymeans of his own breath rhythmically forcing air into the patients lungsand sucking it out. This mouth to mouth insuillation method has longbeen known and practiced but is subject to definite limitations. In therst place, it is possible to exert toomuch pressure, thus doing damageto the alveoli, especially in the case of premature infants. In thesecond place, it is impossible to maintain such treatment for long,especially in cases with anaerobic suppuration of the lung because ofthe fetor; and in the third place, it has the disadvantage that theopverted from a resuscitator into an inhalator, or vice Versa.

The term oxygen is used herein broadly to include not only 100% oxygenbut any gas or mixture of gases for insuilating a patients lungs orcombating asphyxia. The invention will best be understood if thefollowing description is read in connection with the accompanyingdrawing, in which Figure 1 is a front view of my apparatus largely incross-section; e

Figure 2 is a front elevational view of my de- Vice;

Figure 3 is a detail sectional view of valve means for converting thedevice from a resuscitator to a simple inhalator, taken to the rear ofthe section of the valve shown in Figure 1;

Figure 4 is asectional view taken longitudinally along the line 4-4through the valve means shown in Fig. 3.

Figure 5 is a detail view largely in cross-section indicating the iiowof gases in the apparatus during inhalation;

Figure 6 is a detail view largely in cross-section indicating the flowof gases in the apparatus during exhalation; and

Figure 7 is a detail sectional view taken at line 'I-`1 of Fig. 2illustrating the crankl connection pin in the inactive position.l

The numeral I0 indicates the body portion of a device embodying myinvention and has therein inhalation passageway II and exhalationpassageway I2 which at its top communicates with the passageway I Iintermediate its ends. Eachv of the passageways II and I2 is providedat'the` lower endwith screw threaded sockets I3 and I4 to receive theends of conduits I3' and I4 for communication with a patientsrespiratory system, preferably through a mask M, (see Fig. 2) which isplaced over the patients mouth and nose, and has a mouth piece, as willbe well understood by those skilled in this art.

At its upper end the inhalation passage I I has a socket I5 forconnection to a pressure reducing unit identied in the drawing as P. R.Unit of an oxygen tank shown in Fig. 1 or to an intermediate tube orhose. A high speed nozzle IB having a bore of very small diameter isprovided in inhalation passageway I I to increase the speed of flow ofthe oxygen therein, thereby creating suction in the exhalationpassageway I2, which opens into passage II adjacent the ejection end ofthe nozzle I6, through portal S. As shown in Figure 1, a plug I5 isthreaded in the top of the device in alinement with said nozzle topermit insertion and removal of the nozzle. from adjacent the oxygeninlet coupling I5 around nozzle I6 is an inhalation by-pass I'I whichalso opens into inhalation passage rII through portal S. By-pass I'Iinsures that an amount of oxygen sufficient for the patients needs willbe supplied to the inhalation passage.

As illustrated in Figs. l, 5, and 6 a rotatable Valve R is provided inportal S whereby during insuiliation the passageway I2 will be'cut offand oxygen' be supplied both through the nozzle Iii and the by-pass I'I(Fig. 5), whereas during exhalation by-pass I'I will be closed and thegas exhausted from the patients lung will flow upwardly through passageI2 into passageway II and will be vented through port Hp (Fig. l),

which is closed during insulation by the upturned portion of the slidevalve to be described. The means for actuating Valve R is hereinafterdescribed.

A slide valve having a horizontal portion I8 and a vertically extending4flange portion IB, is provided with the horizontal portion slideablyseated in slideway I9 extending across passages II and I2 at rightangles thereto, and with the ange portion |81 extending upwardly overthe front exterior of the device. In the horizontal portion of slidevalve I8 are ports ISa and Ib adapted to register with passageways IIand I2 respectively for alternately opening and cutting offcommunication between passages Il and I2 and the patients lungs. PortsIa and i812 are spaced so that only one of them may be in register withits passageway at a time, the port that is open being closed and theclosed port opened on each reciprocation of the slide.

Upturned portion I8f of the slide valve is adapted to slide over portsIIp and I2p which extend horizontally through the front wall of thedevice and communicate respectively with the passageways II and I2. Inthe upturned portion |87' of the slide valve I8 is a port IBp, which atthe end of each reciprocation of valve I8 is in register either withport IIp or I2p. During exhalation, when port Ib is in register withpassageway I2, ports |810 and Ilp will be in register, and port I2p willbe closed; and during insufllation, when port Ia is in register withpassageway I I, ports I8p and I2p will be in register and port IIp willbe closed.

When rotary valve R is employed to close communication betweenpassageways II and I2 during insufiiation, port I2p is not required. Insome cases, however, it is desirable to dilute the oxygen supplied tothe patient, and in such cases Extending connected, and valve R employedas a stationary Valve to close passage I1 while port 12p is employed asan air intake port during inhalation.

As illustratedherein the portion of inhalation passageway II between thetip of the nozzle I6 and slide valve I8 is in the form of a Venturitube, which serves, with the high speed jet of oxygen from nozzle I6, tocreate suction at portal S to draw the exhalation gases from passage I2into passage II and expel them through ports IIp and I3p duringexhalation (Fig. 6), or to draw air into passage I2 through ports Ip and|212 the means for reciprocating valve R may be disand thence intopassage II to be mixed with the oxygen, when valve R is not employed asa reciprocating valve. The nozzle I6 may be screw threadedly fitted intothe top of passageway II which is fashioned to receive it and has a bore2U of very narrow diameter provided with a screen 2| positioned at itsupper end to prevent particles of dust and dirt from clogging it. Thescreen may be held in pla-ce by means of screw cap 22 threadedly engagedwithin the concavity provided therefor in the top of the nozzle I6.Intermediate the ends of the bore 2 but adjacent the tip of the nozzleI6 an air chamber 23 is provided which communicates, through radiallyextending ports 24, with passage II opposite portal S. Gaseous fluidsfrom passage I2 or I'I are drawn into the nozzle I6 through ports 24 andejected through the tip of the nozzle, or drawn through the channel 25surrounding the periphery of the reduced tip of nozzle I6, between thetip of the nozzle and the wall of the inhalation passageway II. v

Slide-valve I8 is reciprocated by movements of pressure sensitive member42 induced as will be further explained by variations in pressure in mydevice corresponding with the pressure in the patients lungs,transmitted through bell crank 3 I, pivoted to the body I0 of the deviceat 32, and its spring arm 30. After a predetermined degree of rotationof the bell crank 3i about its pivot in either direction, in a manner tobe described, the spring arm 3U moves from engagement with one of a pairof permanent magnets 33a and 33h into engagement with the other of saidpermanent magnets and during the course of this movement engages one ofthe pins m and n projecting from the face of the slide valve ange I 8fthereby reciprocating the slide valve. The pins m and n are positionedon valve flange I8 so that arm 3l) will not strike either of them whenmoving in either direction until it has entirely freed itself `from themagnet with which it was last engaged and has gained momentum, so thatwhen the contact occurs the slide valve I8 will be moved sharply andpositively the full distance required to open one of passageways II orI2 and close the other. The permanent magnets are slideably mounted inslots 34 provided in bracket 35 secured on the front of the body portionI0 of `my device, so that the distance between each of them and springarm 30 and its pivot 32 may be adjusted. As illustrated the bracket is aunitary member having outwardly extending anges 36 inclined toward oneanother in the direction of pivot 32 and secured on the body portion I0of the device by means of screws 31 extending through the lugs 38 on thebracket. If desired the flanges 36 may comprise part of a continuousshield or cover extending over the ports Ilp and |250, the arm 30, andthe permanent magnets 33a and 33h.

It will be noted that, as illustrated in Figure 2, lpermanent magnet 33ais positioned somewhat near-'er pivot 32 than permanent magnetv 33h.Thepressure required to disengage spring arm 30: from permanent magnet33a will therefore be Vless than is required to disengage it `frompermanent magnet 33h'. Spring arm 30 is engaged with `magnet 63a. duringexhalation and. it will thus vbe seen that a lesser suction pressurewill be exerted on the patients lungs during exhalation than .thepositive pressure exerted during insuillation. Very satisfactory resultsare attained by selecting and positioning the parts of my device so thatthe contact between arm 3U and permanent magnet 33h will be broken whena positive pressure of 4 ounces per square inch is attained in thepatients lungs, and the contact between arm 3i) and magnet 33a will bebroken when a negative pressure of 3 ounces per square inch is developedin the patients lungs.

Below slide valve I8 a small pressure equalizing .by-pass- Ais providedbetween `passages II and I2.` Opening from inhalation passage II 'belowslide valve I8 is a passageway 4i) communieating through conduit 4I andcoupling 4Ia with the bellows 42 which is adapted to expand upwardlywhen gas under positive pressure is introduced therein and to deate whenthe positive pressure is cut off and 'a negative pressure is'communicated thereto. At the top of bellows 42 a pin 43 is providedwhich `extends through arm 44 of bell crank 3| and has thereon two halfspherical lmembers 43a and 43h the spherical surfaces of which engagethe opposite faces of arm 4'4. The arm 44 is thus engaged ata point andis capable of some rocking action during the periods-of expansion andcontraction ofthe bel'- lows While the positive or negative pressure inthe patients lungs and in passages II and I2 below slide valve I8 arebuilding up to the predetermined pressure necessary to move the bellows4Z, bell crank 3l and spring arm'SIl sufficiently to break the contactbetween spring arm `attraction of the magnet with which it is inContact.

The rotary valve R extends through the body portion I0 of the device andas shown in Fig. 2 has the exterior arm orA crank 56, which is slottedat 5I to receive pin 52 fixed on bell crank 6I. Valve R will thus berotated synchronously with bell crank 3I and therefore with thereciprocations of slide valve I8. If for the purpose of diluting theoxygen supply it is desired to draw air into the device through port |2pand mix it with the oxygen in passageway II during insuiiiation, thismay be accomplished by placing valve R in the position indicated in Fig.6 and the dotted position indicated in Fig. 2, and disengaging pin 52from slot 5I. To this end pin 52 is desirably provided with annulargrooves 52a and 52h which cooperate withV the spring detent 53 insecuring the pin 52 in active or inactive position. In Fig. '7, pin 52vis in inactive position,

The ability of arm 3!) to swing sharply from one magnet to the other isenhanced by spring the upper end of which is attached to pin 4Bprojecting from the front face of the device near; itsy top, andthelower-.end of whichisseillustrated cured to pin 41 projecting fromarm 36 near its lower end. It will be noted that the force exerted .byspring 45 will be greatest when arm 30 is midway between the extremitiesof its arc of movement and` will thus `accelerate the pendulum-likemovement of arm 30 after passingthis point in either direction.

Positioned in inhalation passage II adjacent passage 4] leading to thepressure responsive member 42 is a conical valve 60, Figures 1, 3 and 4,which serves to close conduit 40 and passage II, and open passageways.6I and 62 lead*- ing to and from an auxiliary gas reservoir -T,indicated in dotted lines in. Figs. land 3 for the purpose of providingan even supply of oxygen during inhalation, when it is desired to usethe device as a simple inhalator insteadfof as a resuscitator. Thepassageways 6I and 62 communicate with conduits 63 and 66 respectivelyleading to the inlet and outlet ports 64 and 65 of said auxiliary `gasreservoir by means of annular grooves 68 and 68 Vprovided in conicalvalve (see Fig. 4). At some convenient place, such as the connection tothe said auxiliary gas reservoir T, an intake valve 64 is alsopreferably provided, which opens to admit atmospheric air if for anyreason the reservoir becomes exhausted and the amount of oxygen beingsuplied to the patient through the device is insuftlcient.

It will be readily understood that when gaseous fluid is not flowinginto `or out of the member 42 it will be stationary and consequentlyslide valve I8 and valve R will remain stationary and in order to changethe device from use as a resuscitator to a simple inhalator it is onlynecessary to set valve R to thev position shown in Fig. 1, and turnvalve 66 in accordance with the marking on the lower face of the deviceA(see Fig. 2). As shown, valve 6D is yjournalled in a tapered seat 60which intersects the pase sage II at right angles. A handle 'I2 issecured on offset portion 'II or" valve 6I! and the nut 'I3 is securedon another reduced portion of' the valve at its rear end and abutsagainst spring 'I4 intermediate it and the rear wall II) of the deviceto seat and seal the valve 60 properly while permitting its freerotation. Valve 66 is partly cut away at 61 forming a concavity incommunication with passage II (Fig. l), and from this cut away portion,a passage 61 extends to the peripheryv of the valve and is brought intoalinement with conduit 40 while the device 'is being used asaresuscitator. Adjacent its 'rear end, valve 60 has two partial anfnular grooves or passages 68 and 63' communicating between inlet channel6I and outlet channel 62 with the respective inlet and outlet conduits63 and 66 leading to and from the inlet and outlet ports 64 and B5 ofauxiliary gas reservoir T while the device is being used as an in-vhalator.

When the device is used simply as an inhala` tor, exhalation will beaccomplished through a one-way valve in the mask (see Fig. 2)- withwhich my device communicates. While the device is used as a resucitatorthis valve is not reflow through passage II directly to the patientslungs and al'sothr'ough conduits 40 andV 4I into` bellows 42 to operatecrank arm 3I causing reciprocations of the spring arm 30 as thepressures in bellows 42 is increased during inhalation or decreasedduring exhalation. In corresponding movements the valve I9 willalternately open and close inhalatio-n passage II and exhalation passageI2. The inhalation passage II communicates with conduit I3 (shown inFig. 2) leading to mask M which is placed over the patients face andconduit I4 leading from the said mask communicates with exhalationpassage I2. When the device is used as a simple respirator the handlel2, shown in Fig. 2, is positioned so that conical valve Eil will be inthe position indicated in Fig. 4 thereby closing communication throughconduits MI and 4I to the bellows, which is utilized duringresuscitation to cause crank 3| and therefore spring arm 30 toreciprocate thus operating slide valve I9 and causing inhalation andexhalation pressures to be built up alternately, but is not needed whilethe device is used as a simple respirator. Besides cutting off bellows42, conical valve 60 closes the main passage through the lower portionof passageway II but opens an alternative passage which passes throughthe auxiliary gas reservoir T. The use of this auxiliary gas supplyduring respiration insures a reserve supply and therefor an even supplyof oxygen irrespective of the evenness of the flow in the upper portionof passageway I I.

While the device is used as a respirator the gas from the oxygen tankpasses through passage II, port 6I, annular groove G6 (Fig. 3) inconical valve 60, conduit 63 to the inlet 64 of auxiliary gas reservoirT and from the gas reservoir through outlet of said gas reservoir T,conduit 66, and annular groove E8' of conical valve 6I! and outlet port62 into the lower end of passage I I, and through conduit I3 to the maskM, shown in Fig, 2, from which it is inhaled by the patient. Gasesexhaled by the patient do not pass through the conduit I4 and outletpassageway I2 but are exhausted directly from the mask M through thevalve illustrated on the mask and identified as Exhalation valve.

What I claim is:

1. A resuscitation device comprising an inhalation passage adapted to beconnected intermediatea source of oxygen supply and a patients lungs, anexhaust passage adapted to be connected to the patients'lungs and anintermediate portion of the inlet passage, valve means positioned belowthe point of intercommunication between said passages for simultaneouslyopening one of said passages and closing the other, a pressureresponsive member, a conduit leading from said inhalation passage belowthe saidvreciprocable valve to the said member, said reciprocable valvehaving a plurality of spaced contact members, a pivoted arm adapted toengage one of said contacts when it is travelling in one direction andthe other contact when it is travelling in the other direction, meansconnected between said pressure responsive member and said pivoted armfor actuating said arm, and means positioned adjacent respective ends ofthe path of said pivoted arm adapted to engage said arm and hold ituntil a predetermined opposing pressure is exerted on the arm.

2. An inhalation and resuscitation device comprising an inhalationpassage adapted to be connected intermediate a source of oxygen supplyand a patients lungs, an exhaust passage adapted to be connected to thepatients lungs and an intermediate portion of the inlet passage, anauxiliary inlet passage opening into the inhalation passage at its pointof junction with the exhaust passage, valve means for alternatelycutting oi communication between said inhalation passage and saidexhaust passage o-r said auxiliary inlet, and a reciprocable valve forclosing either said inhalation passage or said exhaust passage andsimultaneously opening the other passage when a predetermined positiveor negative pressure has been built up therein, a duct communicatingbetween said inhalation and exhalation passages below the saidreciprocable valve, a pressure responsive member, a conduit connectingsaid member with the inhalation passageway below the said reciprocablevalve, means controlled by the movement of said member for reciprocatingboth of said valves in synchronism, and means for disconnecting saidinhalation passageway and the pressure responsive member and therebypreventing reciprocation of said valve so that the device may beemployed as an inhalator.

3. An inhalation and resuscitation device comprising an inhalationpassage adapted to be connectedfintermediate a source of oxygen supplyand a patients lungs, an exhaust passage adapted to be connected to thepatients lungs and an intermediate portion of the inlet passage, anauxiliary inlet passage opening into the inhalation passage at its pointof junction with the exhaust passage, valve means for alternatelycutting off communication between said inhalation passage and saidexhaust passage or said auxiliary inlet, and a reciprocable valve forclosing either said inhalation passage or said exhaust passage andsimultaneously opening the other passage when a predetermined positiveor negative pressure has been built up therein, a duct communicatingbetween said inhalation and exhalation passages Vbelow the saidreciprocable valve, a pressure responsive member, a conduit connectingsaid member with the inhalation passageway below the said reciprocablevalve, means controlled lby the movement of said member forreciprocating both of said valves in synchronism,

a gas reservoir, conduits connecting the reservoir with said inhalationpassageway below the said reciprocating valve and means fordisconnecting said inhalation passageway and the pressure responsivemember, thereby preventing reciprocation of said valve so that thedevice may be employed as an inhalator, and simultaneously connectingsaid passage with the conduits of said gas reservoir.

4. A resuscitation device comprising an inhalation passage adapted to beconnected intermediate a source of oxygen supply and a patients lungs,an exhaust passage adapted to be connected to the patients lungs and anintermediate portion of the inlet passage, an auxiliary inlet passageopening into the inhalation passage at its point of junction with theexhaust passage, Valve means for alternately cutting oli communicationbetween said inhalation passage and said exhaust passage or saidauxiliary inlet, and valve means for closing either said inhalationpassage or said exhaust passage and simultaneously opening the otherpassage when a predetermined positive or negative pressure has beenbuilt up therein, a duct communicating between said inhalation andexhalation passages below the said valve, a pressure responsive member,a conduit connecting said member with one of said passageways below thesaid valve, and means controlled by the movement of said member forreciprocating both of said valves in synchronism and means positioned atthe respective ends of the path of travel of said pivoted member toengage it with a predetermined force. i

5. A resuscitation device comprising an inhalation passage adapted to beconnected intermediate a source of oxygen supply and a patients lungs,an exhaust passage adapted to be connected to the patients lungs and anintermediate portion of the inlet passage, an auxiliary inlet passageopening into the inhalation passage at its point `of junction with theexhaust passage, valve means for alternately cutting off communicationbetween said inhalation passage and said exhaust passage or saidauxiliary inlet, and valve means for closing either said inhalationpassage or said exhaust passage and simultaneously opening the otherpassage when a predetermined positive or negative pressure has beenbuilt up therein, a duct communicating between said inhalation andexhalation passages below the said valve, a pressure responsive member,a conduit connecting said member with one of said passageways below thesaid valve, and means controlled by the movement of said member forreciprocating both of said valves in synchronism,

an ,intake port in said exhaust passage, a vent in the device and thepatients lungs for actuating said valve including a pivotedpendulum-like arm, means for reciprocating said arm, a pair of magnetspositioned and adapted respectively to engage said arm with apredetermined force at the extremities of its travel, and means foropera-y tively engaging said valve and arm during the latters travel ineither direction.

y7. A device for mechanically insuiating and deflating a patients lungsincluding an inhalation channel and an vexhalation channel adapted to beconnected between a source of oxygen and the patients lungs, a valve forsimultaneously opening one of said channels and closing the other, meanscontrolled by gas pressure within the channel and the patients lungs foractuating said valve including a pivoted pendulum-like arm,

a pair of magnets positioned and adapted to engage said arm with apredetermined force at the extremities of its travel, means foroperatively engaging said valve and arm during the latters travel ineither direction, a valve in said exhalation channel, and means movablewith said arm for operating said valve in synchronism with said rstmentioned valve.

8. A device adapted to alternately create positive and negativepressures in a patients lungs or alternatively to supply gas to beinhaled and exhaled by the patient, comprising, an inhalation passageadapted to be connected intermediate a source of gas supply and apatients lungs, an exhaust passage adapted to be, connected intermediatea patients lungs and said inhalation passage, a slide valve extendingtransversely of said inhalation and exhaust passages having a porttherein adapted to register alternately with said passages, a vent inthe wall of each of said passages, means for operatingsaid valve member,and means actuated by said valve for closing the vent in the passagewith which the port in the said slide valve is in register.

9. A device adapted to alternately create positive and negativepressures in a patients lungs or alternatively to supply gas to beinhaled and exhaled yby the patient, comprising, an inhalation passageadapted tobe connected intermediate a source of gas supply and apatients lungs, an exhaust passage adapted to be connected intermediatea patients lungs and said inhalation passage, a slide valve extendingtransversely of said inhalation and exhaust passages having a porttherein adapted to register alternately with said passages, a vent inthe wall of each of `said passages, and means actuated by said valve forclosing the Vent in the passage with which the port in the saidslidevalve is in register, a pressure responsive member, a conduitconnecting said pressure member with said inhalation passage, and meanscontrolled by the movement of said pressure member for reciprocatingsaid slide valve.

10. A device adapted to alternately create positive and negativepressures in a patients lungs or alternatively to supply gas to beinhaled and exhaled by the patient, comprising, an inhalation passageadapted to be connected intermediate a source of gas supply and apatients lungs, an exhaust passage adapted to be connected intermediatea patients lungs and said inhalation passage, valve means forsimultaneously opening one of said passages and closing the other, apressure responsive member, a conduit connecting said pressureresponsive member with said inhalation passage, and means controlled bythe movement of said pressure responsive member for actuating said valvemeans, and a duct communicating between said inhalation and exhalationpassages, said duct and said conduit connecting the pressure member Withthe inhalation passage being located on the same side of said valvemeans.

11. A device adapted to alternately create positive and negativepressures in a patients lungs or alternatively to supply gas to lbeinhaled and exhaled by a patient, comprising, an inhalation passageadapted to be connected intermediate a source of gas supply and apatients lungs, an exhaust passage adapted to be connected intermediatea patients lungs and said inhalation passage, valve means forsimultaneously opening one of said passages and closing the other, apressure responsive member, a conduit connecting said pressure memberwith said inhalation passage, and means controlled by the movement ofsaid pressure member for reciprocating said slide valve, a chamber forstoring oxygen, a conduit connecting said inhalation passage to saidchamber, and valve means for alternately closing one of said conduitsand opening the other.

12. A device adapted to alternately create posi,- tive and negativepressures in a patients lungs or alternatively to supply gas to beinhaled and exhaled by the patient, comprising, an inhalation passageadapted to be connected intermediate a source of gas supply and apatients lungs, an exhaust passage adapted to be connected intermediatea patients lungs and said inhalation passage, a slide valve extendingtransversely of said inhalation and exhaust passages having a porttherein adapted to register alternately with said passages, a vent inthe wall of each of said passages, and means actuated by said valve forclosing the vent in the passage with which the port in the said slidevalve is in register, and an additional inlet for supplying gas, openinginto the inhalation passage at its point of junction with the exhaustpassage, and valve means for alternately connecting said additionalinlet or said exhaust passage to said inhalation passage.

13. A device adapted to alternately create positive and negativepressures in a patients lungs or alternatively to supply gas to beinhaled and exhaled by Va patient, comprising, an inhalation passageadapted to be connected intermediate a source of gas supply and apatients lungs, an exhaust passage adapted to be connected intermediatea patients lungs and said inhalation passage, valve means forsimultaneously opening vone of said passages and closing the other, apressure responsive member, a conduit connecting said pressure memberwith said inhalation passage, and means controlled by the movement ofsaid pressure member for reciprocating said slide valve, a chamber forstoring oxygen, a conduit connecting said inhalation passage to saidchamber, and Valve means for alternately closing one of said conduitsand opening the other, an additional inlet for supplying gas openinginto said inhalation passage at its point of junction with nthe exhaustpassage, and valve means for alternately connecting the inhalationpassage to said auxiliary inlet and to said exhaust passage.

HORACE H. RAYMOND.

